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51.
Extracts of paw paw ( Asimina triloba, Annonaceae) are among the most potent of the 3500 species of higher plants screened for bioactive compounds in our laboratories at Purdue University. The paw paw is a small tree native to eastern North America; its edible fruits (sometimes referred to as "Indiana Bananas") have nurtured mankind for centuries. Activity-directed fractionation of the paw paw extracts, using the brine shrimp lethality bioassay, led to the isolation and molecular characterization of over 50 unique annonaceous acetogenins. Fractionation of extracts from related species resulted in the identification of over 150 additional acetogenins. The annonaceous acetogenins are derivatives of long-chain (C32 or C34) fatty acids. They are potent inhibitors of mitochondrial (complex I) as well as cytoplasmic (anaerobic) production of adenosine triphosphate (ATP) and the related nucleotides. The powerful cytotoxicity, in vivo antitumor, pesticidal, antimalarial, anthelmintic, piscicidal, antiviral, and antimicrobial effects indicated a myriad of potentially useful applications. Commercial development of these compounds uses natural mixtures of active components, incorporated into pesticidal, topical, and dietary supplement products. Successful applications and commercial products include a shampoo, highly effective in treating infestations of head lice, fleas, and ticks; a series of pesticidal sprays, which protects host plants against a diversity of pests; and an ointment for treatment of oral herpes (HSV-1) and other skin afflictions. The extract (in capsule form) enhances a mixture of natural anthelmintics. In addition, an encapsulated extract has been effectively used by certain cancer patients as a botanical supplement product.  相似文献   
52.
Background: Positive correlations have been reported between wastewater SARS-CoV-2 concentrations and a community’s burden of infection, disease or both. However, previous studies mostly compared wastewater to clinical case counts or nonrepresentative convenience samples, limiting their quantitative potential.Objectives: This study examined whether wastewater SARS-CoV-2 concentrations could provide better estimations for SARS-CoV-2 community prevalence than reported cases of COVID-19. In addition, this study tested whether wastewater-based epidemiology methods could identify neighborhood-level COVID-19 hotspots and SARS-CoV-2 variants.Methods: Community SARS-CoV-2 prevalence was estimated from eight randomized door-to-door nasal swab sampling events in six Oregon communities of disparate size, location, and demography over a 10-month period. Simultaneously, wastewater SARS-CoV-2 concentrations were quantified at each community’s wastewater treatment plant and from 22 Newport, Oregon, neighborhoods. SARS-CoV-2 RNA was sequenced from all positive wastewater and nasal swab samples. Clinically reported case counts were obtained from the Oregon Health Authority.Results: Estimated community SARS-CoV-2 prevalence ranged from 8 to 1,687/10,000 persons. Community wastewater SARS-CoV-2 concentrations ranged from 2.9 to 5.1log10 gene copies per liter. Wastewater SARS-CoV-2 concentrations were more highly correlated (Pearson’s r=0.96; R2=0.91) with community prevalence than were clinically reported cases of COVID-19 (Pearson’s r=0.85; R2=0.73). Monte Carlo simulations indicated that wastewater SARS-CoV-2 concentrations were significantly better than clinically reported cases at estimating prevalence (p<0.05). In addition, wastewater analyses determined neighborhood-level COVID-19 hot spots and identified SARS-CoV-2 variants (B.1 and B.1.399) at the neighborhood and city scales.Discussion: The greater reliability of wastewater SARS-CoV-2 concentrations over clinically reported case counts was likely due to systematic biases that affect reported case counts, including variations in access to testing and underreporting of asymptomatic cases. With these advantages, combined with scalability and low costs, wastewater-based epidemiology can be a key component in public health surveillance of COVID-19 and other communicable infections. https://doi.org/10.1289/EHP10289  相似文献   
53.
54.
The purpose of this study was to evaluate the effectiveness of the DI Flashcard system for teaching preliminary mathematic skills to three preschool students. The participants attended a self-contained special education preschool. All three participants’ eligibility category was “developmentally delayed”. A concurrent multiple baseline design across three sets (colors, shapes, and numerals) was use to evaluate the effectiveness of the DI flashcard system. The results indicated that all three participants showed an increase in their performance when DI flashcards were in effect. However, the amount of improvement varied for each participant. The importance of employing evidence-based procedures to teach skills to preschool students with developmental delays was outlined.  相似文献   
55.
This paper reports on a study that explored the perceptions of students and lecturers regarding support within a pre-registration midwifery programme in one Higher Education Institution in England. A mixed method design was used: questionnaires were completed by first year and third year students and lecturers, complemented by focus groups with each of the three sets of participants. The findings showed that there are multi-focal challenges for student midwives in undertaking their programme of study. The main theme that emerged was of the difficulties involved in maintaining an appropriate work–life balance, especially within what was seen as a relatively inflexible programme structure. The value of peer support was also highlighted as a key factor in helping the students succeed in their studies. There were a number of implications for midwifery educators to consider in optimising support for students. These include ensuring that students have realistic expectations at the outset of their studies, formalising peer support mechanisms and reviewing programmes to provide more flexibility to better underpin the maintenance of an appropriate work–life balance. Further study is warranted to explore perceptions of support in practice and to identify the factors that help students to persevere in their studies.  相似文献   
56.
Glucocorticoids are potent anti-inflammatory molecules used in the treatment of asthma, rheumatoid arthritis, inflammatory bowel disease, and other inflammatory and dermatological diseases, as well as in posttransplantation immunotherapy. Although glucocorticoids have been prescribed for many years, their potential side effects, when administered orally, can prevent their long-term use. The most serious side effect observed in the clinic is glucocorticoid-induced osteoporosis (GIOP). To develop a small animal model to characterize glucocorticoid-induced bone loss, we carried out a series of experiments using BALB/c mice given daily intraperitoneal doses of the synthetic glucocorticoid, dexamethasone. Following dexamethasone treatment, the mice became osteopenic, with highly significant decreases in bone formation rate and mineral apposition rate, as assessed by standard histomorphometry. Moreover, 3 week treatment with dexamethasone resulted in a decrease in trabecular thickness and trabecular number with an increase in surface-to-volume ratio of trabeculae in the distal femur, as measured using microcomputed tomography (micro-CT). The serum bone formation marker, osteocalcin, was dose-dependently decreased in all mice treated with dexamethasone and showed a parallel extent of regulation to the bone formation rate changes. In addition, serum levels of leptin, recently identified as playing a role in the regulation of bone mass, increased following dexamethasone treatment. BALB/c mice therefore represent a useful model system in which the detrimental effects of glucocorticoids on bone can be studied.  相似文献   
57.
ObjectiveThe goal of this study was to identify a microRNA (miRNA) signature in bladder cancer capable of differentiating superficial from invasive disease.MethodsExpression profiling of 343 miRNAs was performed in a microarray format using noninvasive and invasive bladder carcinoma cell lines with differential expression confirmed using a single molecule detection platform assay. miR-21 and miR-205 expression levels were determined in 53 bladder tumors (28 superficial and 25 invasive). Sensitivity, specificity, and a ROC curve were calculated to determine the discriminatory power of the miRNA ratio to predict invasion. Knockdown and forced expression of miRNAs was performed to evaluate their role in invasion.ResultsExpression profiling of 343 miRNAs, using noninvasive and invasive bladder cell lines, revealed significant differential expression of 9 miRNAs. Cell lines characterized as invasive showed a miR-21:miR-205 ratio at least 10-fold higher than the quantitative ratio obtained from non-invasive cell lines. The same expression ratio was determined in 53 bladder tumors. From these results, we recorded a sensitivity and specificity of 100% and 78%, respectively, using a cutoff of 1.79 to predict an invasive lesion. The area under the receiver operator characteristic curve was 0.89. Using in vitro invasion assays, we have demonstrated a role for miR-21 in establishing the invasive phenotype of bladder carcinoma cells.ConclusionIn this study, we identified a miR-21:miR-205 expression ratio that has the ability to distinguish between invasive and noninvasive bladder tumors with high sensitivity and specificity, with the potential to identify superficial lesions at high risk to progress.  相似文献   
58.
In vivo and in vitro studies have shown that alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-receptor-mediated excitotoxicity causes cytoskeletal damage to axons. AMPA/kainate receptors are present on oligodendrocytes and myelin, but currently there is no evidence to suggest that axon cylinders contain AMPA receptors. Proteolipid protein (PLP) and DM20 are integral membrane proteins expressed by CNS oligodendrocytes and located in compact myelin. Humans and mice lacking normal PLP/DM20 develop axonal swellings and degeneration, suggesting that local interactions between axons and the oligodendrocyte/myelin unit are important for the normal functioning of axons and that PLP/DM20 is involved in this process. To determine whether perturbed glial-axonal interaction affects AMPA-receptor-mediated axonal damage, AMPA (1.5 nmol) was injected into the caudate nucleus of anesthetized Plp knockout and wild-type male mice (n = 13). Twenty-four hours later, axonal damage was detected by using neurofilament 200 (NF 200) immunohistochemistry and neuronal damage detected via histology. AMPA-induced axonal damage, assessed with NF 200 immunohistochemistry, was significantly reduced in Plp knockout mice compared with wild-type mice (P = 0.015). There was no significant difference in the levels of neuronal perikaryal damage between the Plp knockout and wild-type mice. In addition, there was no significant difference in the levels of glutamate receptor subunits GluR1-4 or KA2 in Plp knockout compared with wild-type littermates. The present study suggests that PLP-mediated interactions among oligodendrocytes, myelin, and axons may be involved in AMPA-mediated axonal damage.  相似文献   
59.
The purpose of the present study was to evaluate the outcome of primary uncemented total hip arthroplasty in patients younger than 50 years using the Taperloc (Biomet, Warsaw, Ind) femoral component. We evaluated 94 hips in 79 patients at a mean follow-up of 16 years (range, 11-18.5 years). The average age of the patients at the time of surgery was 36 years (range, 20-49 years). Three femoral components had been revised, none for aseptic loosening. Complete clinical and radiographic follow-up was obtained on the 91 hips that had not undergone femoral component revision. The mean Harris hip score increased from 54 points (range, 20-72) before surgery to 93 points (range, 68-100) at the time of this review. Radiographically, 89 stems (98%) were determined to have fixation by bone ingrowth, 2 (2%) demonstrated stable fibrous ingrowth, and no femoral component was loose. Distal femoral osteolysis was identified in 1 hip (1%). These findings indicate that excellent clinical and radiographic results can be achieved in young patients with the Taperloc femoral component at a mean follow-up of 16 years.  相似文献   
60.
Changes in regional coronary flow after administration of intracoronary nitroglycerin were assessed by measuring total coronary blood flow (using coronary sinus flow catheters) and its regional distribution (by quantitative single-photon emission tomography of injected radioactive microspheres). After pacing to angina, 10 patients with coronary artery disease received serial selective left coronary injections of technetium-99m microspheres, 40 micrograms of nitroglycerin, and indium-111 microspheres. Significant changes in coronary flow distribution were determined by subtracting prenitroglycerin from postnitroglycerin tomographic profiles. Perfusion of each myocardial segment was classified as normal mildly, moderately or severely compromised, based on upstream coronary anatomy. The overall increase in coronary flow was 23% in the normal territories and 33%, 44% and 15% (p less than 0.05), in the mildly, moderately and severely compromised territories, respectively, compared with control values. Thus, intracoronary nitroglycerin increased coronary blood flow to all perfusion territories. The increase in distribution of coronary flow was greatest in the mildly and moderately compromised regions and the least in the most severely compromised regions; this is probably a reflection of the underlying coronary reserve.  相似文献   
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